1. Field of the Invention
The present invention relates to a vibration source probe system for specifying and displaying the source of a vibration which is generated on a road or at a factory.
2. Description of the Prior Art
Low-frequency vibrations are generated from machine tools and the like installed at a factory together with noises. These vibrations are perceived as vibrations from the ground or the floor of a building. On a road or in a house near an intersection where there is heavy traffic, vibrations coming from the above road together with noises generated by the passage of trucks cause a problem.
In general, as the source of a vibration is identical to the source of a noise in most cases, the method of estimating the source of a vibration by sampling a noise from the above machine tool or truck to specify the source of the noise is effective. However, when many machine tools are installed near walls and surrounded by partitions or when there is a wall or building between a place where the source of a vibration passes, such as an intersection and a place where a vibration is perceived, a noise is reflected by the above reflector complicatedly, thereby making it difficult to specify the source of the noise itself. Since a sound generated together with a vibration when a truck or the like runs over a depression or manhole in a road has a very low frequency, it is difficult to locate the source of the sound.
Meanwhile, there is known a method of specifying a seismic center as means of specifying the source of a vibration. This method is to calculate the distances between a plurality of measurement points and the seismic center from a difference (initial fine movement time) between the arrival times of the P wave (vertical wave) and S wave (horizontal wave) of seismic waves measured by a seismograph at the plurality of measurement points so as to obtain the seismic center from the above calculated distances from the measurement points. It is possible to obtain the coordinates of the seismic center if there are at least three measurement points.
However, a vibration from a vibration source at the factory or on the road, such as the above machine tool or truck is generally a continuous vibration (surface wave) which is different from the P wave or S wave corresponding to the main vibration of the seismic waves. In addition, the vibration to be detected is mixed with vibrations from a plurality of vibration sources, thereby making it impossible to specify the starting point of the vibration from a specific vibration source. Therefore, even if the above method of obtaining the seismic center is directly employed, it is difficult to specify the above vibration source.